Maine-based photographer Tanja Hollander set out to find the answer about five years ago when she began connecting with and photographing her 600-plus Facebook friends in their living rooms. At the time of the interview, she was at number 417 with the hope of at least connecting with them all by the end of 2015.

Her travels have taken her to 43 states and five other countries and are archived in about 15,000 images and videos. Her last photography session was at the end of October in Boston.

“It’s been really fun but also really exhausting. I realized I’ve been on the road almost four years straight,” Hollander said during a phone interview last week.

The idea originated while she was handwriting a letter to a friend deployed in Afghanistan, and simultaneously emailing another working in Jakarta, Indonesia.

“I kept thinking about those two kinds of friendship. They were people from different parts of my life, but who were both really important. … I started scrolling through lists of Facebook friends, some of whom I hadn’t met in real life — they were professional contacts, friends of friends — and others I hadn’t seen in many years.”

How many of them, she wondered, were her real friends? How many would agree to meet with and open their homes up to her?

Hollander is well-known for her landscape photography (she earned a B.A. in photography, film and feminist studies in 1994 from Hampshire College in 1994) and her work has been exhibited nationally in New York City, Boston and Portland, Maine, galleries.

Her project — which will decorate the Massachusetts Museum of Contemporary Art when it’s completed in 2017 — will include these photos and also video installations and notes from viewers that answer things like, “What is friendship?”

Fifteen of these short films will screen at Southern New Hampshire’s McIninch Art Gallery Feb. 26 through April 4. They will be projected on the gallery walls, and though the ideal time to view “Are You Really My Friend?” will be during Hollander’s artist reception Feb. 26, viewers can come in anytime during gallery hours and navigate through the images with an iPad connected to the projector. McIninch Art Gallery Director Debbie Disston hopes both the university community and the general public will take a look.

“Our students are so engaged in social media, that it just seemed like a perfect project for a university community,” Disston said. “It addresses all the issues that not just students but also staff deal with in terms of how people use social media, what the constraints and strengths are, how it informs the work and how students use it to socialize. It’s so ingrained in their lifestyle.”

On the gallery’s outside wall, visitors will be asked to contribute to Hollander’s notes by sharing their thoughts about friendship with Post-its. She’s already collected thousands from her show’s viewers. She’s learned a bit about friendship and relationships herself.

“People have been overwhelmingly positive. I’ve had a couple of close friends say no, but I’ve stayed with people I hadn’t met before,” Hollander said. “I wasn’t an outgoing, friendly person before, and I definitely am now. You have to be. You can’t be a jerk going into people’s homes. ... I’ve been surprised, continually surprised, by how kind and generous people are, and how proud they are of where they live. Almost across the board, people have been excited to take me to a favorite park or museum or restaurant or festival.”